Soil organic carbon （SOC） sequestration is one of the major agricultural strategies to mitigate greenhouse gas （GHG） emissions, enhance food security, and improve agricultural sustainability. This paper synthesize...Soil organic carbon （SOC） sequestration is one of the major agricultural strategies to mitigate greenhouse gas （GHG） emissions, enhance food security, and improve agricultural sustainability. This paper synthesizes the much-needed state- of-knowledge on the effects of tillage, crop residue, and nutrient management practices on SOC sequestration and identifies potential research gap, opportunities, and challenges in studying SOC dynamics in rice （Oryza sativa L.）-based cropping systems in South Asia, mainly in Bangladesh, Bhutan, India, Nepal, Pakistan, and Sri Lanka. Improved management prac- tices such as reduced- and no-tillage management, nitrogen （N） fertilizer and farmyard manure （FYM） application, and crop residue addition can improve SOC accumulation. Positive effects of no-tillage, crop residue addition, N addition through manure or compost application, and integration of organic and chemical fertilizers on SOC accumulation in rice-based cropping systems have been documented from South Asia. However, limited data and enormous discrepancies in SOC measurements across the region exist as the greatest challenge in increasing SOC sequestration and improving agricultural sustainability. More research on SOC as influenced by alternative tillage, crop residue, and nutrient management systems, and development of SOC monitoring system for existing long-term experiments will advance our understanding of the SOC dynamics in rice-based cropping systems and improve agricultural system sustainability in South Asia.展开更多
Introduction:Griseofulvin is an antifungal drug belonging to Biopharmaceutical Classification System(BCS class II)having low solubility.Objectives:To formulate,evaluate and enhance the dissolution of poorly water solu...Introduction:Griseofulvin is an antifungal drug belonging to Biopharmaceutical Classification System(BCS class II)having low solubility.Objectives:To formulate,evaluate and enhance the dissolution of poorly water soluble drug Griseofulvin by using solid dispersion method.Methods:Six formulations were prepared by solid dispersion method using Polyethylene Glycol(PEG 6000)125 mg,0 mg,62.5 mg,100 mg,25 mg,150 mg and superdisintegrants Crospovidone 0 mg,125 mg,62.5 mg,100 mg,25 mg,150 mg in all batches respectively.Findings:Satisfactory results were obtained from evaluation of physical characteristics of Griseofulvin tablets including:carr’s compressibility index(17.5±0.19%to 11.76±0.67%),Hausner ratio(1.21±0.01 to 1.13±0.02)and post compression parameters including:thickness(5.16±0.02 mm to 4.57±0.19 mm),friability(0.024%to 0.322%),hardness(4±0.28 kg/cm^(2)to 5±0.57 kg/cm^(2)),disintegration time(14-870 seconds).Conclusions:F3 was best formulation among all formulated batches with in-vitro drug release 30.05%in 10 minutes,69.21%in 30 minutes and 97.11%in 45 minutes.This indicated that formulation F3 batch with PEG 6000 of 62.5 mg and crospovidone 62.5 mg showed increased dissolution.展开更多
Tillage management that minimizes the frequency and intensity of soil disturbance can increase soil carbon(C)and nitrogen(N)sequestration and improve the resilience of dryland cropping systems,yet the impact of occasi...Tillage management that minimizes the frequency and intensity of soil disturbance can increase soil carbon(C)and nitrogen(N)sequestration and improve the resilience of dryland cropping systems,yet the impact of occasional disturbance on soil aggregate formation and the soil organic carbon(SOC)storage within aggregates has not been studied well.We evaluated the effect of four tillage management practices on soil dry aggregate size distribution,aggregate-protected C and N,mineral-associated organic matter carbon(MAOM-C),particulate organic matter carbon(POM-C),and corn(Zea mays L.)and sorghum(Sorghum bicolor(L.)Moench)yields in a semi-arid dryland cropping system.Treatments included conventional tillage(CT),strip-tillage(ST),no-tillage(NT),and occasional tillage(OT)management in a corn-sorghum rotation.Soil macro-aggregates were 51-54%greater under ST,NT,and OT,while small and micro-aggregates were greater in CT.Conventional tillage reduced soil aggregate-associated C by 28-31%in macro-aggregates and 47-53%in small aggregates at 26 months(M)sampling compared to ST,NT,and OT.In clay+silt fraction,CT had 14-16%,21-26%,and 36-43%less SOC at 7,14,and 26M samplings,respectively,than ST,NT,and OT.Aggregate associated N was generally similar under ST,NT,and OT,which was greater on average than CT.Soil MOAM-C and POM-C under ST,NT,and OT were generally greater than respective SOC fractions under CT at 19 and 26 M after OT implementation.Corn and sorghum yields were similar among tillage systems in 2020,but greater under ST,NT,and OT than CT in 2021.Our results suggest that while frequent intensive tillage can lower SOC and N storage,a single stubble mulch occasional tillage after several years of NT does not lead to soil C and N losses and soil structural instability in semi-arid drylands.展开更多
文摘Soil organic carbon （SOC） sequestration is one of the major agricultural strategies to mitigate greenhouse gas （GHG） emissions, enhance food security, and improve agricultural sustainability. This paper synthesizes the much-needed state- of-knowledge on the effects of tillage, crop residue, and nutrient management practices on SOC sequestration and identifies potential research gap, opportunities, and challenges in studying SOC dynamics in rice （Oryza sativa L.）-based cropping systems in South Asia, mainly in Bangladesh, Bhutan, India, Nepal, Pakistan, and Sri Lanka. Improved management prac- tices such as reduced- and no-tillage management, nitrogen （N） fertilizer and farmyard manure （FYM） application, and crop residue addition can improve SOC accumulation. Positive effects of no-tillage, crop residue addition, N addition through manure or compost application, and integration of organic and chemical fertilizers on SOC accumulation in rice-based cropping systems have been documented from South Asia. However, limited data and enormous discrepancies in SOC measurements across the region exist as the greatest challenge in increasing SOC sequestration and improving agricultural sustainability. More research on SOC as influenced by alternative tillage, crop residue, and nutrient management systems, and development of SOC monitoring system for existing long-term experiments will advance our understanding of the SOC dynamics in rice-based cropping systems and improve agricultural system sustainability in South Asia.
基金This research received no specific grant from any funding agency in public,commercial,or not-for-profit sectors.
文摘Introduction:Griseofulvin is an antifungal drug belonging to Biopharmaceutical Classification System(BCS class II)having low solubility.Objectives:To formulate,evaluate and enhance the dissolution of poorly water soluble drug Griseofulvin by using solid dispersion method.Methods:Six formulations were prepared by solid dispersion method using Polyethylene Glycol(PEG 6000)125 mg,0 mg,62.5 mg,100 mg,25 mg,150 mg and superdisintegrants Crospovidone 0 mg,125 mg,62.5 mg,100 mg,25 mg,150 mg in all batches respectively.Findings:Satisfactory results were obtained from evaluation of physical characteristics of Griseofulvin tablets including:carr’s compressibility index(17.5±0.19%to 11.76±0.67%),Hausner ratio(1.21±0.01 to 1.13±0.02)and post compression parameters including:thickness(5.16±0.02 mm to 4.57±0.19 mm),friability(0.024%to 0.322%),hardness(4±0.28 kg/cm^(2)to 5±0.57 kg/cm^(2)),disintegration time(14-870 seconds).Conclusions:F3 was best formulation among all formulated batches with in-vitro drug release 30.05%in 10 minutes,69.21%in 30 minutes and 97.11%in 45 minutes.This indicated that formulation F3 batch with PEG 6000 of 62.5 mg and crospovidone 62.5 mg showed increased dissolution.
基金This research was funded by project No.GR0006188 of the USDA Natural Resources Conservation Service,New Mexico.The study plots were established with funding from the New Mexico State University Agricultural Experiment Station.
文摘Tillage management that minimizes the frequency and intensity of soil disturbance can increase soil carbon(C)and nitrogen(N)sequestration and improve the resilience of dryland cropping systems,yet the impact of occasional disturbance on soil aggregate formation and the soil organic carbon(SOC)storage within aggregates has not been studied well.We evaluated the effect of four tillage management practices on soil dry aggregate size distribution,aggregate-protected C and N,mineral-associated organic matter carbon(MAOM-C),particulate organic matter carbon(POM-C),and corn(Zea mays L.)and sorghum(Sorghum bicolor(L.)Moench)yields in a semi-arid dryland cropping system.Treatments included conventional tillage(CT),strip-tillage(ST),no-tillage(NT),and occasional tillage(OT)management in a corn-sorghum rotation.Soil macro-aggregates were 51-54%greater under ST,NT,and OT,while small and micro-aggregates were greater in CT.Conventional tillage reduced soil aggregate-associated C by 28-31%in macro-aggregates and 47-53%in small aggregates at 26 months(M)sampling compared to ST,NT,and OT.In clay+silt fraction,CT had 14-16%,21-26%,and 36-43%less SOC at 7,14,and 26M samplings,respectively,than ST,NT,and OT.Aggregate associated N was generally similar under ST,NT,and OT,which was greater on average than CT.Soil MOAM-C and POM-C under ST,NT,and OT were generally greater than respective SOC fractions under CT at 19 and 26 M after OT implementation.Corn and sorghum yields were similar among tillage systems in 2020,but greater under ST,NT,and OT than CT in 2021.Our results suggest that while frequent intensive tillage can lower SOC and N storage,a single stubble mulch occasional tillage after several years of NT does not lead to soil C and N losses and soil structural instability in semi-arid drylands.
